Question

The concentration of $A{g}^{+}$ in a saturated solution of $A{g}_{2}Cr{O}_4$ at ${20}^0$C is $1.5\times {10}^{-4}mol{L}^{-1}$. The solubility product of $A{g}_{2}Cr{O}_4$ at ${20}^{0}C$ is ?

• A. $1.687\times {10}^{-12}$
• B. $1.75\times {10}^{-10}$
• C. $3.0\times {10}^{-8}$
• D. $4.5\times {10}^{-10}$

Answer 1

The correct option is A $1.687\times {10}^{-12}$

Reaction is : $A{g}_{2}Cr{O}_4\rightleftharpoons 2A{g}^{+}+Cr{O}_4^{2-}$

$A{g}^{+}=1.5\times {10}^{-4}$M

$Cr{O}_4^{2-}=0.75\times {10}^{-4}M\left(\frac{1}{2}ofA{g}^{+}\right)$

so ,$K_{sp}=(1.5\times {10}^{-4}{)}^2\times (0.75\times \times {10}^{-4})=1.687\times {10}^{-12}$